<?php
/*
* accept-to-gettext.inc -- convert information in 'Accept-*' headers to
* gettext language identifiers.
* Copyright (c) 2003, Wouter Verhelst <hide@address.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Usage:
*
* $locale=al2gt(<array of supported languages/charsets in gettext syntax>,
* <MIME type of document>);
* setlocale('LC_ALL', $locale); // or 'LC_MESSAGES', or whatever...
*
* Example:
*
* $langs=array('nl_BE.ISO-8859-15','nl_BE.UTF-8','en_US.UTF-8','en_GB.UTF-8');
* $locale=al2gt($langs, 'text/html');
* setlocale('LC_ALL', $locale);
*
* Note that this will send out header information (to be
* RFC2616-compliant), so it must be called before anything is sent to
* the user.
*
* Assumptions made:
* * Charset encodings are written the same way as the Accept-Charset
* HTTP header specifies them (RFC2616), except that they're parsed
* case-insensitive.
* * Country codes and language codes are the same in both gettext and
* the Accept-Language syntax (except for the case differences, which
* are dealt with easily). If not, some input may be ignored.
* * The provided gettext-strings are fully qualified; i.e., no "en_US";
* always "en_US.ISO-8859-15" or "en_US.UTF-8", or whichever has been
* used. "en.ISO-8859-15" is OK, though.
* * The language is more important than the charset; i.e., if the
* following is given:
*
* Accept-Language: nl-be, nl;q=0.8, en-us;q=0.5, en;q=0.3
* Accept-Charset: ISO-8859-15, utf-8;q=0.5
*
* And the supplied parameter contains (amongst others) nl_BE.UTF-8
* and nl.ISO-8859-15, then nl_BE.UTF-8 will be picked.
*
* $Log: accept-to-gettext.inc,v $
* Revision 1.1.1.1 2003/11/19 19:31:15 wouter
* * moved to new CVS repo after death of the old
* * Fixed code to apply a default to both Accept-Charset and
* Accept-Language if none of those headers are supplied; patch from
* Dominic Chambers <hide@address.com>
*
* Revision 1.2 2003/08/14 10:23:59 wouter
* Removed little error in Content-Type header syntaxis.
*
*/
/* not really important, this one; perhaps I could've put it inline with
* the rest. */
function find_match($curlscore,$curcscore,$curgtlang,$langval,$charval,
$gtlang)
{
if($curlscore < $langval) {
$curlscore=$langval;
$curcscore=$charval;
$curgtlang=$gtlang;
} else if ($curlscore == $langval) {
if($curcscore < $charval) {
$curcscore=$charval;
$curgtlang=$gtlang;
}
}
return array($curlscore, $curcscore, $curgtlang);
}
function al2gt($gettextlangs, $mime) {
/* default to "everything is acceptable", as RFC2616 specifies */
$acceptLang=(($_SERVER["HTTP_ACCEPT_LANGUAGE"] == '') ? '*' :
$_SERVER["HTTP_ACCEPT_LANGUAGE"]);
$acceptChar=(($_SERVER["HTTP_ACCEPT_CHARSET"] == '') ? '*' :
$_SERVER["HTTP_ACCEPT_CHARSET"]);
$alparts=@preg_split("/,/",$acceptLang);
$acparts=@preg_split("/,/",$acceptChar);
/* Parse the contents of the Accept-Language header.*/
foreach($alparts as $part) {
$part=trim($part);
if(preg_match("/;/", $part)) {
$lang=@preg_split("/;/",$part);
$score=@preg_split("/=/",$lang[1]);
$alscores[$lang[0]]=$score[1];
} else {
$alscores[$part]=1;
}
}
/* Do the same for the Accept-Charset header. */
/* RFC2616: ``If no "*" is present in an Accept-Charset field, then
* all character sets not explicitly mentioned get a quality value of
* 0, except for ISO-8859-1, which gets a quality value of 1 if not
* explicitly mentioned.''
*
* Making it 2 for the time being, so that we
* can distinguish between "not specified" and "specified as 1" later
* on. */
$acscores["ISO-8859-1"]=2;
foreach($acparts as $part) {
$part=trim($part);
if(preg_match("/;/", $part)) {
$cs=@preg_split("/;/",$part);
$score=@preg_split("/=/",$cs[1]);
$acscores[strtoupper($cs[0])]=$score[1];
} else {
$acscores[strtoupper($part)]=1;
}
}
if($acscores["ISO-8859-1"]==2) {
$acscores["ISO-8859-1"]=(isset($acscores["*"])?$acscores["*"]:1);
}
/*
* Loop through the available languages/encodings, and pick the one
* with the highest score, excluding the ones with a charset the user
* did not include.
*/
$curlscore=0;
$curcscore=0;
$curgtlang=NULL;
foreach($gettextlangs as $gtlang) {
$tmp1=preg_replace("/\_/","-",$gtlang);
$tmp2=@preg_split("/\./",$tmp1);
$allang=strtolower($tmp2[0]);
$gtcs=strtoupper($tmp2[1]);
$noct=@preg_split("/-/",$allang);
$testvals=array(
array($alscores[$allang], $acscores[$gtcs]),
array($alscores[$noct[0]], $acscores[$gtcs]),
array($alscores[$allang], $acscores["*"]),
array($alscores[$noct[0]], $acscores["*"]),
array($alscores["*"], $acscores[$gtcs]),
array($alscores["*"], $acscores["*"]));
$found=FALSE;
foreach($testvals as $tval) {
if(!$found && isset($tval[0]) && isset($tval[1])) {
$arr=find_match($curlscore, $curcscore, $curgtlang, $tval[0],
$tval[1], $gtlang);
$curlscore=$arr[0];
$curcscore=$arr[1];
$curgtlang=$arr[2];
$found=TRUE;
}
}
}
/* We must re-parse the gettext-string now, since we may have found it
* through a "*" qualifier.*/
$gtparts=@preg_split("/\./",$curgtlang);
$tmp=strtolower($gtparts[0]);
$lang=preg_replace("/\_/", "-", $tmp);
$charset=$gtparts[1];
#header("Content-Language: $lang");
#header("Content-Type: $mime; charset=$charset");
return $curgtlang;
}
?>